Method of constructing suspension assemblies



c T. HUTC'HENS METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES Oct. 22,1968

7 Sheets-Shee t 1 Original Filed June 15, 1965 INVENIOR Cr /741225 TA wow/u AQQ4/Z4M ATTORNEYS Oct. 22, 1968 C; T. HUTCHENS 3,406,439

METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES Original Filed June 15, 1965 7 Sheets-Sheet 2 Oct. 22, 1968 c. "r. HUTCHENS METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES 7 Sheets-Shet 5 Original Filed June 15, 1965 ATTORNEYS 1968 c. T. HUTCHENS 3,406,439

METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES Original Filed June 15, 1965 7 Sheets-sheaf;

INVENTOR 67/144455 TflUTCAE/VS ATTORNEYS Oct. 22, 1968 c. T. HUTCHENS METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES '7 Sheets-Sheet 5 Original Filed June 15, 1965 QQQQ INYRAQQ m RQ MQR INVENTOR 6209/94 53 7. /V0rc4ems' ATTORNEY 3 Oct. 22, 1968 c. T. HUTCHENS 3,406,439

METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES Original Filed June 15, 1965 7 Sheets-Sheet 6 is t INVENTOR 6HARLES T. HUTCHENS ATTORNEYS Oct. 22, 1968 c. T. HUTCHENS METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES 7 Sheets-Sheet '7 Original Filed June 15, 1965 as. wax QQM United States Patent 3,406,439 METHOD OF CONSTRUCTING SUSPENSION ASSEMBLIES Charles T. Hutchens, 1131 S. Kentwood, Springfield, Mo. 65804 Application June 15, 1965, Ser. No. 464,166, now Patent No. 3,279,815, dated Oct. 18, 1966, which is a continuation-in-part of application Ser. No. 179,328, Mar. 13, 1962, now abandoned. Divided and this application Sept. 16, 1966, Ser. No. 579,929

Claims. (Cl. 29155) This application is a division of my copending application, Ser. No. 464,166, filed June 15, 1965, now Patent No. 3,279,815, granted Oct. 18, 1966, which, in turn, is a continuation-in-part of my copending application, Ser. No. 179,328, filed Mar. 13, 1962, now abandoned.

The invention relates to improvements in methods of constructing suspension assemblies for vehicles and, more especially, to a new concept in a single and multiple axle suspension. The invention is particularly concerned with the production of a suspension unit having a minimum number of parts and requiring a minimum number of fabricating steps.

In the construction of tandem suspension units, including sliders, bogies and the like, for trailers, trucks, etc., it is known that there must be a bogie frame as long or slightly longer than the spring or springs under each vehicle to support the suspension unit, axles and so forth. The bogie frame and related parts are welded, bolted, or otherwise fastened to the bottom of the vehicle bed in the usual method of manufacture. Each bogie frame usually consists of two longitudinal beams or rails provided with cross members to keep the rails in place and provide suitable bracing. The spring hangers, trunnion mounting bracket, torque arm mountings, and the like attachments are then fastened underneath the bogie frame, after which the springs, axle mounting housings, torque arms, axles and wheels may be joined thereto.

It is known that these parts may be joined to the vehicle body in any feasible sequence, and sometimes, separate groups of parts are fabricated into a sub-assembly, which is then joined to the whole. Whatever presently known fabricating method is followed, however, the result may well be subject to misalignment and problems of imbalance, unless great care is observed. This is sometimes correctible with the use of adjustable torque arms, but the result has not been completely satisfactory. Further, some presently known tandem suspension units are objectionably high in cost and yet do not offer satisfactory alignment.

For example, in one known method of manufacture, the rails, cross members, spring hangers, axles and wheels, etc., are assembled together to form a slider which is a separable bogie unit, resembling a dolly, that is adapted to be secured in a variety of positions along a vehicle body. The unit may be adjusted in location with respect to the vehicle, to suit state laws, and may even be removed from one body to another, as each body becomes worn out. However, this type of unit is objectionably expensive because of high initial cost in fabricating a well aligned unit from a great variety of separate parts. The number of parts heighten the possibility of error, and the requisite cost to be substantially free of error is almost prohibitive.

In a more preferred construction, the spring hangers and torque arm hangers are separately mounted, although they are not ordinarily fastened directly to the frame of the vehicle. Instead, the spring hangers, including the hangertfor springs, torque arms, and equalizer in a tandem unit, are individually attached to a sub-frame composed 3,406,439 Patented Oct. 22, 1968 of rails and cross members, that is built under that part of the vehicle body adapted to receive the spring hangers, etc. Mounting of these parts is followed by attachment of the suspension units including springs, axles and wheels. If the spring hangers are not very accurately placed and fastened, malalignment of the springs, axles, and wheels will result. This occurs "very frequently, sometimes to the extent that it cannot be corrected by adjustable torque arms. Also, when the spring hangers are being individually attached (in addition to the danger of placing one too far back or too far forward, which frequently happens), if the spring hanger is not welded or bolted on in exact parallel alignment with the frame, this will cause considerable wear and frequently cause the axles and wheels to be out of alignment.

Hence, much of the presently known tandem unit is put together from many parts, creating possibilities of weakness and malalignment that increase from part to part. There are also possibilities of misalignment that can cause trouble in actual operation and these difficulties cannot be simply overcome with the use of an adjustable torque arm. Other objections to suspension systems of present practice will become apparent in the body of this specification when reference is had to the advantages offered by the present invention.

It is an object of this invention to provide a novel fabrication process for the manufacture of a vehicle suspension permitting great savings in labor, and establishing a basis for hitherto unexpected precision in tandem suspension construction at remarkably low cost.

Other and further objects of this invention, together with an appreciation for the advantages thereof, will become increasingly apparent as this description proceeds.

Broadly stated, the objects of this invention are accomplished, advantages are realized, and prior art defects are overcome by fabricating a suspension assembly principally comprising a pair of side rails that are integrally connected by cross members and secured by various reinforcing members. According to the invention, each side rail includesat least two and preferably three integral hanger sections depending therefrom, with two of the hanger sections being disposed substantially at each end of the side rail, and the third hanger section being substantially intermediate the two hanger sections. Each hanger-section preferably tapers from top to bottom. A plurality of hanger side plates are also provided that are substantially identical to each of the hanger sections. Each hanger side plate is disposed inwardly of a corresponding hanger section and is integrally connected to the suspension assembly, thereby defining a spring hanger bracket with the corresponding hanger section.

The concept of unitized tandem is realized primarily in that the side rails and integral hanger sections are stamped out in one piece, or cast in one piece. The hanger side plates, cross members, and reinforcing members are preferably formed in the same way. Because of the one piece side rail construction, there is no possibility of misalignment and the entire unit is much easier to install. The manufacturers cost is much less because there are fewer parts to weld or bolt together. The vehicle suspension will also save a great deal of labor in the manufacture of the completed trailer because of fewer parts, and because of predetermined, accurate alignment. It is also the feature of integrally joining all parts into one part, preferably by welding, that characterizes this inventive development as a unitized tandem, or a unitized suspension assembly or system.

With the procedures according to this invention, the prior art defects are principally overcome because the spring hangers are built into and form an integral part of the bogie frame so that the whole vehicle suspension, including frame, can be fastened to the bottom of a truck or trailer bed in one operation.

This vehicle suspension will have the advantage of being much less expensiveto the manufacturer than the current practice'of either manufacturing a suspension unit from separately purchased parts, or of purchasing the frames separately, installing them, and then having the suspension unit, including spring hangers and so forth, fastened to the frame. The cost to the manufacturer at present to buy the frame and buy the suspension unit separately, is well in excess of three hundred dollars. With the present invention, on the other hand, fabricators will be able. to market a complete suspension unit, with springs, axles and so forth, including all parts that go into the usual suspension assembly, for a'price in the neighborhood of two hundred dollars. This is a remarkable saving in a highly competitive field. I

Other advantages are also realized with the procedures of this invention. For example, the height of the unit from the 'road or the height above the road at which it is desired to support the truck or trailer bed can be easily varied due to the unique manner of fabricating the side rails. As an illustration, the height of the unit illustrated herein can be varied from a fraction of an inch to as much as a plus or minus eight or more inches. Normally, vertical height variations of a plus or minus three or four inches is considered entirely adequate. This ability to vary off the road height is a matter of particular importance when tandems are being installed to replace either single axle units or worn out tandem units on existing equipment. Very frequently in the installation of replacement units, a support height that is different from the height of the stock replacement unit is desired. It has been the practice that a fabricating shop is required to cut off, or more frequently, fill in between the ordinary sub-frame and the actual truck or trailer frame. This, of course, can be done by adding an extra piece of steel channel, girder, plate or casting, but this type of makeshift alteration increases thelikelihoodof misalignment, etc. Also, such changes alter the design characteristics of the replacement unit, and may give rise to premature failure, vibration, sway, and the like. With the procedures of the present invention on the other hand, variatin in height is an easy matter that will permit manufacture in different heights to suit different customers desires.

However, the chief difference of the suspension unit constructed according to this invention, from prior known tandem suspensions, is that in the device constructed according to the invention, the spring hangers and other attachments to the 'two side rails of the subfra me are stamped out and formed as an integral part of such sub frame. There is great advantage to doing this, particularly when compared to a construction procedure that requires bolting or even welding on of the spring hangers as well as other attachments because each such spring hanger or attachment has to be separately and carefully located 'in the exact position where it is to be bolted on or welded on. A'ver-y slight deviation can cause excessive Wear or even cause the springs to come out of the spring hangers. On the other hand, where the whole unit is stamped out and made as one piece, as is done according to the present invention, these major errors in alignment (and even minor errors)in the location of the spring hangers on the suspension unit, are completely avoided because all parts are stamped, formed and bent in identical dies. In this manner, one may eliminate wear and other troublesome objections that occur with the usual way of putting a suspension unit together and fastening it in place because all essential alignment is accurately pre determined by the dies. Still other advantages of this procedure will become apparent at the end of this specification:

Other and further advantages of the present invention will become increasingly apparent as this description pro- 4 ceeds, but the understanding of the invention will now' be facilitated by reference to the drawings, wherein:

FIGURE 1 is a perspective view of acompleted suspension unit constructed according to the invention;

FIGURE 2. is a broken out perspective view, greatly enlarged, of the left hand rear-spring hanger assembly of the suspension unit shown in FIGURE l;

FIGURE 3 is a broken out perspective view, also greatly enlarged/of the right hand rear spring hanger assembly of the suspension unit shown in FIGURE 1; FIGURE 4 is a side elevation view of the suspension unit as it would appear in assembled configuration with suitable springs and the like;

FIGURE 5 is a side elevation view of a blanked side rail for the suspension unit of FIGURE 1, and represents the first stage of production prior to any forming operations; I

' FIGURE 6 is a side elevation of the blanked'side rail of FIGURE 5 following the forming operation to turn the bottom lining flange of the threehanger sections with the aid of a suitable forming die, and thereby represents the second stage of production; FIGURE 7 is a perspective view taken from the in side of the blanked and formed side rail of FIGURE 6, following a braking operation to provide upper and lower channel areas thereon, and thereby represents the third and final'stage' of production thereof; 1 i FIGURE 8 is an outside perspective view of i the blanked, formed, and broken side rail of'FIGURE 7 to show details of the lower channel members and formed hanger sections; V

FIGURE 9 is aninside elevation view of a typical blanked left hand rear inside hanger side plate (cf. FIGf URE 1) prior to any forming operations, and represents the first stage of production thereof; FIGURE 10 is a'side elevation view similar to FIG: URE 9 of the same hanger side plate following the forming operation to turn the bottom lining flange, and thereby represents the second stage of production thereof;

FIGURE 11 is an elevation view of the blanked and formed side plate of FIGURE 10 but taken from th e opposite side thereof and following the braking operation to provide the upper channel thereon, and thereby represents the third and final production stage of atypical hanger side plate according to the invention} 1 FIGURE 12 is a schematic diagramshowing the se} quence of forming operations used in producing the sus; pension unit according to the invention including the steps of forming the side rails, insidehangerplates, cross rails and reinforcing flanges; I I FIGURE 13 is a vertical sectional view, on an enlarged scale, taken substantially along line 13-13-of FIGURE 4 to show details of the central hanger section and spring equalizer bracket; I M FIGURE 14 is a sectional view, on an enlarged scale, taken substantially along line 14 14 of FIGURE, 4 to show details ofthe torque arm axle mounting. housing; FIGURE 15 is a sectional view on a similarscale, taken along line15 15 0f FIGUREv 4. to shovvotherde tails of the axle mounting housing. in relation to theaxle; FIGURE 16 is a plan view of anaxle mountinghousing side plate on still a greater scale; and ,4 FIGURES 17 and 18 are side elevation and top plan views, respectively (FIGURE-18 shows left and right ends only), on an enlarged scale, of the rigid torque arm shown in FIGURE 4. st :Turning now to FIGURE 1 of the drawings, the suspension unit or single unit sub-frame constructed according to'the invention is designated generally by thereferen'ce numeral 20 and is composedof' two mirror image side rails 22. The side rails 22 are preferably provided with upperrigidiffingchatinel sections 24 and lower rigidifyin'g channel sections 26 reinforced with the flanges '23. FIG URES 5 to 8, showing'the sequence of producing'the side rails, also serve to illustrate the channel sections 24 and 26, as do FIGURES 2, 3 and 4.

Each upper edge rigidifying channel 24 is preferably continuous for the length of the side rail and is integrally formed therewith from a plate piece of side rail stock plate so as to be turned inwardly ofthe side railwith respect to the completed sub-frame. The channel 24 has the general shape of an inverted L with respect to the sub-frame,.in that the siderail forms the body of the L, and the channel has a base that is approximately perpendicular, to the plane of the side rail, and a lip depending from such base that is approximately parallel to the plane of the side raiL The lower edge rigidifying channel 26 is also continuous in the sense that it is formed in part from the flat stock of the side rail and in part from the flat stock of the hanger side plate described hereinafter. The channel 26 is preferably disposed inwardly of the side rail with respect to the sub-frame. The channel 26 has the general shape of an L that is rotated about 90 from the vertical suchthat the body and lip of the L are approximately perpendicular with .respect to the plane of the side rail, and such that the base of the L is approximately parallel to the plane of the side rail. Preferably, the channels 24. and 26 are in parallel alignment with each other, such that in cross section they will generally have the shape of a figure 5 with the substantially vertical straight leg of the figure representing the plane of the side rail. Other channel section shapes and locations can also be employed, but those illustrated in the drawing are to be preferred.

As shown in the drawings, there are preferably six reinforcing flanges 28 integrally attached to each side rail on the inside thereof with respect to the sub-frame, although more or fewer such flanges may be employed. Preferably, the reinforcing flanges 28 are disposed in approximately parallel alignment between the channels 24 and 26.

The illustrated flanges 28 resemble a triangular shape in plan view with the hypotenuse described an acute angle between the channel 26 and the inside face of the side rail 22. It is preferred that each. reinforcing flange 28 has a stabilizing element or lining flange 29 along the hypotenuse side thereof.

The two side rails 22 are connected together by any.

desired number of reinforcing cross beams or cross members 30. Four such cross members 30 are preferred. The cross members 30 on each end are preferably defined by a central plate 31 having a lower turned out flange 32 and an upper turned in flange 34. The central cross members are preferably U shaped channel sections such that the flanges 32 and 34 face in the same direction. The members 30 are preferably produced by blanking a flat plate followed by braking in the desired direction to form the flanges 32 and 34. The cross members 30 are integrally joined to the side rails 22 by welding, preferably to -the inside face of the hanger side plates described hereinafter and this connection is preferably reinforced by the flange plates 36 welded to the top flange 34 and to the channel member 26 across the point of connection.

The illustrated end cross beams 30 are approximately Z shaped in cross section. They are formed by blanking a flat piece of stock plate followed by braking the upper and lower, edges thereof in opposite directions along parallel lines. It is preferred that the central cross beams 30 are approximately U shaped in cross section. They are formed by blanking flat stock, followed by braking the upper and lower edges thereof in the same direction along parallel lines. The reinforcing web flange member 36 is preferably a flat plate that may be approximately triangular in shape, or pentagonal, and is integrally secured along a side edge thereof to the respective cross member 30, and along a base edge thereof to the upper face of thhe reinforcing channel 26.

According to this invention, it is an important featurethat each of the side rails 22 is provided with integral depending hanger sections 42, 44, and 46. Each hanger section is provided with a corresponding hanger side plate 52, 54, and 56 defining therebetween a spring hanger 40. Spring mounting pads 58 maybe mounted within the end spring hangers 40, and the trunnion mounting or equalizer member 60 may be received in the spring hangers 40 internally of the hanger sections and side plates 4454. Preferably, each hanger section 42, 44, and 46 has a lining flange 43, and 41 along the edge thereof definingin cross section a smooth curve that leads from the plane of the hanger section and sweeps into and terminates in a straight line that is approximately perpendicular to the plane of the hanger section. The angle of inclination of the lining flange with respect to the plane of the hanger section, may be an angle approaching such as about 30 or more, and maybe greater than'90., although about 90 is preferred for best results. The several lining flanges terminate approximately atthe intersection of the corresponding hanger section with the side rail 22, and it is preferred that each lining flange is turned outward with respect to the sub-frame.

As illustrated, each of the hanger sections taper from top to bottom, and this configuration is presently preferred. In a more limited sense, the end hanger sections approximately resemble a right triangle, and the central hanger section resembles an isosceles triangle, and all hanger sections are rounded at the bottom. It is also preferred that each hanger section merge into the upper side rail plate 22 by means of smooth curves at the area of intersection. Also, the plane of the central hanger section 44 is desirably provided with a raised area or detent 48 that faces out with respect to the subframe and defines an area for receiving the trunnion mounting equalizer bracket 60. Suitable bolt openings 49 are provided to facilitate mounting of the bracket 60 between the central hanger section 44 and the corresponding hanger side plate 54. The central hanger section 44 on each side rail, and the end hanger section 42 on each side rail, as well as the corresponding hanger side plates 54 and 52, are each provided with an opening 51 and 41 toward the respective bottoms thereof. Each of these openings is preferably defined by an area that is raised or turned in with respect to the'spring hanger space 40 between each hanger section and corresponding side plate; These openings and raised areas are adapted to receive a connecting pin or bolt passing through one end of a torque arm described hereinafter.

Each end' spring hanger 40, defined by hanger sections 42 and 46 and corresponding side plates 52 and 56, also receives the integrally fastened spring mounting pad 58 such that the spring mounting pad 58 tends to rigidity the spring hangers with respect to the sub-frame. As best shown in FIGURE 3, each spring mounting pad has a pair of side flanges connected at the upper end by a bearing surface 152 that terminates in the base flanges 153. Suitable holes in the base flanges 153 receive a bolt 154 that passes through a corresponding hole in the flange 32 defining an extension of the cross member 30 between the hanger section 42 and the hanger side plate 52. Tubular bushing 155 at the lower end of the pad '58 receives the bolt 156 which passes through suitable openings 59 in each of the affected hanger sections and side plates.

As to location, it is preferred that with a plurality 'of hanger sections, a hanger section should be located approximately at each end of each side rail, and each end hanger section will generally be the mirror image of the hanger section at the opposite end of each side rail. The central hanger section 44 is then located approximately intermediate the end hanger sections. When the hanger sections 42 and 46 are located at each end of the subframe, they will define the approximate length of each side rail. However, it will sometimes be desired that at least one end of each side rail should extend beyond the corresponding end hanger section, and this modification has been illustrated in the drawings by the dotted lines and extension areas 22'. It is generally intended that the lengths of these suspension units will just extend from the frontof the front hanger to the rear of the rear hanger. With the added sections 22', the rails 22 can extend several inches (e.g., four inches) forward and backward from the respective front and rear hangers. The longer rails can be stamped out by proper dies or they can be supplied by welding on these additional parts. Both long and short rails, of course, can be either permanently fastened to the bottom of a vehicle body or attached as a slider, that is, so attached that they can be positioned with the wheels either forward or backward of any given point.

Referring now to FIGURE 4, there is shown a tandem assembly 20 for attachment to the underside of a vehicle such as a trailer or the like (not shown). The assembly 20 is of symmetrical construction so that only one side is shown. In, FIGURE 4, the unit appears in side elevation substantially as it would appear when mounted on a suitable trailer or other tandem axle vehicle. The unit 20 includes the upper side rail frame 22 carrying forward and rearward leaf spring assemblies 224 and 224', respectively. As shown, the spring 224 is mounted. between the hanger sections 42 and 44. The left end of the spring is received in the spring mounting pad 58 mounted between the hanger section 42 and side plate 52 and the right end of the spring is mounted in the left hand end of the equalizer bracket or trunnion mounting member 60 between the hanger sections 44 and 54. Similarly, the right hand end of the member 60 receives the left hand end of the spring 224', the right.hand end of spring 224' being received within the-spring mounting pad 58 mounted between the hanger section 46 and side plate 56. Axle mounting housings, 226 and 226' are operatively joined to the central region of each spring, which housings hold the axles by means described more fully hereinafter. The forward and rearward ends of a torque arm 232 connect the lower end of the hanger sections 42, 52 with the axle mounting housing 226. A similar axle mounting housing 226 is received on the central portion of the right hand spring 224' and a similar torque arm.232 connects the axle mounting housing to the lower portion of the hanger sections 44 and 54.

Turning now to FIGURE 5, there is shown a blanked side rail prior to any forming steps. The blanked side rail is generally defined as a relatively flat rectangular plate having three approximately V-shaped or rounded triangular shaped hanger sections 42, 44 and 46 depending therefrom, as already described. If desired, the side rails 22 may be formed without the end sections 22 indicated by dotted lines. In such case, the side rails would terminate at the ends of the hanger sections. These end sections have, however, been retained throughout the several views for purposes of clarity, it being understood that all fabrication procedures and essential elements of the invention apply whether or not-these end sections are included. Each of the hanger sections 42,44, and 46 is defined in part by cutouts that extend into the body of the flat blanked plate. The cutouts permit formation of lining flanges on the hanger sections as well as the lower channel section 26 in a manner described hereinafter. The overall top to bottom depth of the rectangular portion of the blanked side rail permits formation of both the upper channel section 24 and the lower channel section 26.

In FIGURE 6 the side rail 22 is shown following formation of the lining flanges 43, 45, and 47. In the forming operation, suitable dies act on each of the hanger sections 42, 44 and 46 to provide the outwardly turned lining flanges. These lining flanges provide great rigidity to the otherwise substantially fiat metal area of the hanger sections. According to the invention, this feature aids in the provision of a greatly simplified but rigid construction having minimum number of parts. Also formed during the forming operation is the circular detent 48 in hanger section 44. This detent is provided to facilitate the assembling of the trunnion or equalizer member shown in FIGURES l and 4. Due to formation of the'lining flanges, it is seen that the overall width of each hanger section 42, 44 and 46 is reduced somewhat with respect to the adjacent channel forming sections.

The blanked and formed side rails are next shown in FIGURES 7 and 8 following the braking operation to provide the upper and lower channel sections 24 and 26. The lower channel sections 26 are defined by an inwardly extending horizontal surface, a downwardly extending vertical surface and an outwardly extending horizontal surface as already described hereinbefore. The upper channel members are defined by an inwardly extending horizontal surface and a downwardly extending vertical surface providing a substantially L-shapedchannel'section. As will be understood in the art, the channel members 24 and 26 provide great flexural rigidity to the side rails which otherwise essentially comprise flat rectangular plates. Also, the channel members 24 and 26 provide attachment surfaces for the reinforcing flanges 28 and 36 as well as surfaces for the attachment of the hanger side plates described hereinafter.

The hanger side plates 52, 54, and 56 are variously illustrated in FIGURES l to 4, and 13-. Each hanger side plate 52, 54 and 56 comprises a-relatively -planar area that is provided with a lining flange 53, 55, and 57 around the bottom and side edges thereof. Preferably, the lining flange is turned inward with respect to the sub-frame, and is otherwise quite similar to the lining flanges 43, 45, and 47 on the hanger sections. However, each'lining flange 53, 55 and 57 curves outward from each upper side edge of the respective hanger side plate and terminates in a rounded bottom lining flange at the base of the elongated channel sections 62, 64, and 66 at the top of each hanger side plate. These channels 62, 64 and 66 are turned outward with respect to the sub-frame, and are somewhat elongated with respect to the hanger side plate. After assembly of the sub-frame, the channels 62,64, and 66 form an integral and continuous channel with the lower channel 26 on the side rail 22.

FIGURES 9 to 11 show three steps in the formation of a typical hanger side plate 52, it being understood that the same formation steps will obtain for the production of the remaining hanger side plates 54 and 56, all of which are mounted inside of the side rails and parallel to the corresponding hanger sections 42, 44, and 46 integrally provided on the side rails. In FIGURE 9, the =blanked hanger side plate 52 is shown prior to any forming operations. The blanked side plate is essentially defined by a square or rectangular upper plate area and 21' depending rounded hanger portion resembling the letter V or a somewhat rounded triangle. Suitable holes 41 and 5? are provided for cooperation with the spring mounting pad 58 and for receiving the left hand end of a torque arm. The dotted line area 52 corresponds with the extension 22' 'when this is desired.

In FIGURE 10, the hanger side plate 52 is shown following the operation for forming the lining flange 53, looking at the hanger side plate as it would appear when completed and mounted in the suspension unit to show the lining flange in end view. As with the hanger sections 42, 44, and 46, the lining flange on the hanger side plates 52, 54 and 56 provide strength and reinforcement for purposes of rigidity. In FIGURE 11, the hanger side plate 52 is viewed from the outside as it would appear in the completed suspension unit on the side facing the spring mounting pad 58, following braking to form the channel section 62. Thus, the lining flange is not visible but faces away from the viewer, while the channel member 62 is seen in end view and appears as a set of double lines following the braking operation.

The entire sequence of operations can be visualized by reference to the schematic flow diagram in FIGURE- 12. The side rail forming steps appear in the top of the figure starting with the step of blanking out the side rail to provide the flat blanked out side rail shown in FIG- URE 5. The blanked side rail is then formed to provide the lining flanges as shown in FIGURE 6. Thereafter, the blanked and formed side rail is subjected to the braking operation to provide the completed side rail sections shown in FIGURES 7 and 8 with the upper and lower channels 24 and 26.

Independent of the side rail forming operations but simultaneous therewith as in a continuous production scheme, the hanger side plates 52, 54, and 56 represented by the blanked side plate 52 shown in FIGURE 9 are provided by the blanking operation. Thereafter, the hanger side plates are formed to provide the lining flanges as shown in FIGURE 10. Then, the channel member 62 (FIGURE 11) is formed in a suitable press brake similar to the blanking and braking steps obtained in the formation of the cross rails 30 described in connection with FIGURE 1.

Following the several blanking, forming and braking operations, the side rails, hanger side plates, flanges 28 and 36 and cross rails 30 are assembled in suitable jigs. It is preferred, however, to use a single precision assembly jig which will accurately align the side rails with the remaining parts. Such a jig can be visualized from FIG- URE 1 and need not be described in detail as the shape thereof will vary with design characteristics. Following assembly, all parts are preferably welded or otherwise integrally joined together to provide the unitized tandem suspension unit of the invention. As is understood in the art, welding in essence provides a one-piece or single unit construction.

Referring now to FIGURE 13, it is seen that the central spring hanger 40 includes opposed hanger sections 44 and 54 with a load equalizer bracket 238 mounted between them. The bracket 238 receives the adjacent ends of the leaf spring assemblies 224 and 224', best shown in FIGURES 4 and 14. Fixedly connected between the plates 44 and 54 to receive the bracket 238 is a resiliently mounted equalizer bearing 240 which includes a center sleeve 242 interposed between opposed end plates 244 having apertures therethrough for receiving a bolt 245. A resilient sleeve 246 of rubber or the like is mounted to the exterior surface of the cylindrical sleeve 242. The sleeve 246, in turn, carries the central section 248 of the bracket 238 which includes downwardly converging opposed plates 250 and 252 for receiving the respective ends of the spring assemblies 224 and 224'. The equalizer bracket 238 is secured to a sleeve 254 in snug engagernent with the resilient sleeve 246, as best shown in FIG- URE 13.

The lower ends of the hanger sections 44 and 54 (FIG- URE 13) carry a bolt 262 which in turn receives a sleeve 264 having reinforcing plates 266 joined to the ends thereof. Carried about the sleeve 264 is a resilient sleeve 268 of rubber or the like which normally carries the forward end 230 of the torque arms 232 and 232', as will becorne apparent.

Referring now to FIGURE 14, the axle housing 226 includes a recessed clamping plate 274 having opposed flange portions 276 extending transversely from the bottom thereof. The corresponding visible structure of the axle housing 226' and related elements are designated in FIGURE 4 by corresponding prime numerals. The leaves of the leaf spring 224 have apertures therethrough for receiving a tie bolt 278 which is nested at its upper end within an aligned aperture 279 in the plate 274.

Mounted below the flanges 276 is an upper housing plate 280; and, opposed housing side plates 282 are in normal engagement therewith by four bolts 284. In this regard, the opposed side plates 282 (FIGURES 15 and 16) have transversely bent end portions 286 which re- 10 ceive the bolts 284 to hold the axle housing 226 in place. The opposed side plates 282 have transverse central portions 288 of cylindrical configuration and terminate in inwardly flanged ends 290. The opposed side plates are joined at their lower ends by a nut and bolt assembly 291. Mounted in engagement with the transverse central portions 288 of the opposed side plates 282 is a resilient bearing sleeve 292 having cylindrical end portions 294 and a rectangular central portion 296. The rectangular central portion 296 has an enlarged rectangular interior surface 298 which receives an axle saddle box 300. The axle saddle box 300 has a rectangular exterior surface and a plate 301 with an aperture 302 therethrough of a size corresponding to the interior dimension of the end portion 294 of the resilient sleeve 292 (FIGURE 14). The resilient sleeve 292 is preferably of two-piece, longitudinally split construction and when assembled, forms a generally unitary structure within the axle housing.

The axle housing 226 carries an axle 304 which is secured as by welding to the saddle box 300 at opposed sides thereof. Conveniently, the saddle box 300 may be of split configuration with the upper and bottom portions thereof welded at the axle prior to assembly of the sleeve 292 thereof, as shown in FIGURES 4 and 17.

As stated, the sleeve 292 has a rectangular central portion 296 which is adapted to engage the rearward end of the torque arm 232. To this end, the torque arm 232 is of generally yoke-shaped configuration having rearwardly extending legs 305. A cooperating plate 306 of a generally rectangular configuration is joined to the interior surface of the rearward end of the torque arm 232, and engages the central portion 296 of the resilient sleeve 292. As shown in FIGURES 17 and 18, the torque arm 232 may be constructed of bent metal plate.

The yoke end of the torque arm 232 defined by legs 305 is secured to the axle housing 226 by a vertical tie plate 310, as best shown in FIGURE 15. In this regard, the rearward legs 305 of the torque arm 232 have apertures to receive tie bolts 312, as best shown in FIGURES 4 and 15.

Referring now to FIGURES 17 and 18, the forward end of the torque arm 232 has an aperture 314; and, aligned with this aperture and secured to the interior thereof is a threaded spacer collar 316. Carried and threaded within the spacer collar 316 is a bolt 318 having a nut 320 threaded thereon, and secured to the forward end of the bolt 318 is a bearing collar 322 which is in normal engagement with the resilient sleeve 268 carried by each of the lower ends of the hanger sections 42 and 44 of the side rail 22.

Thus, it is apparent that the torque arm 232 is in planar engagement with the axle housing 226 and is resiliently yieldable with respect thereto by direct engagement with the planar surfaces of resilient sleeve 292. The length of the torque arm 232 is conveniently regulated by loosening the nut 320, turning the bolt 318 to any desired position with respect to the threaded spacer collar 316, and then retightening the jamb nut 320 to secure the new position.

From the foregoing description, it will be apparent that the invention provides a procedure whereby a suspension unit can be manufactured, marketed and delivered at considerably less cost than a comparable suspension assembly that is manufactured from a plurality of separate parts. However, other advantages, besides lower cost and ease of maintenance, are also realized with the construction fabricated according to the invention that overcome serious manufacturing and operating problems.

Up to this time, dual axle spring hangers along with necessary parts have been purchased by trailer manufacturers as separate and unassembled pieces. The manufacturer was required to construct a suitable frame to which the tandem parts were attached either by welding or bolting. This is obviated by the present invention wherein the spring hangers and the structural framework of the complete unit are formed from one piece of metal into one entire side of the unit. Several advantages are gained through this'method'of construction, the principal one being that all sections of this assembly are properly located and are identical since the complete forming operation is performed in a single die. Also, generous weld fillets are possible between the hanger sections and the main frame to build up strength in these critical areas. Even so, the present development actually reduces to a minimum the total number of welding steps and welding time. Further, trailer manufacturers receive parts in a nearly assembled condition. The field assembly costs are reduced to the lowest figure. Frame heights are adjusted in the top area of the frame structure above hanger parts, in a manner already explained.

A common difficulty in the industry is in the location of hangers on the sub-frame so that they are in identical locations from one unit to the next. Fabricators have constant trouble in the field with springs coming out of the hangers and in checking, in practically all instances, it is found that the hangers are located in a slightly dif ferent position than they should be. By having the hangers all made together with the sub-frame according to the present invention, this difficulty is obviated as the hangers will always be located at the same place every time. This type of construction also eliminates the need for plural jigs and fixtures in a manufacturers plant for separately locating the hangers accurately.

The common method of attaching hangers to a frame is either by bolting or welding. Difficulty is encountered in that the bolts become loose on the frame allowing the hangers to break. Also, when welding the hangers separately to the frame, experience shows that the result is always a stress concentration that often results in frame or hanger breakage. This disadvantage is completely obviated according to this invention.

It is often necessary to relocate a complete suspension for different state laws, local ordinances and the like. This is difiicult with present suspensions that are constructed in separate pieces. By proceeding according to the invention, however, having a frame and hangers in a single piece, the entire running gear can be relocated all at one time rather than having to relocate each hanger at a time.

Ordinarily, in having to put the hangers on a conventional frame, one frequently runs into an alignment problem where the hangers or some of them at least, may not be vertical to the ground. This allows for spring wear against the hangers, side plates, etc. This is completely obviated by the present invention. Also, the invention will save time and space in the manufacturing plant because the hangers and frame are in one piece rather than having separate inventories for each and every part.

An important feature that has not been well realized with prior constructions is that of the replacement or slider concept. The present procedure works in very easily with a slider concept, particularly on a body rail of a trailer. The common practice in making a slider is to make a bogie frame, attach the hangers, and then install it under a trailer with a body rail. With the present method of construction, however, there already is a slider and bogie frame assembled together as a single unit, and it is a very simple matter to make a slider out of it.

In reviewing the foregoing description and accompanying drawings, it will be appreciated that the objects of this invention have been successfully achieved. However, the present invention should not be limited to the precise configurations shown in the drawings, as changes and modifications of the structure produced in accordance with the invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.

It will be appreciated that the several parts, particularly the side rail, need not be blanked, formed and broken in one piece where a fabricator may not yet have a press with a large enough bed to blank out the whole side l2 1" s: f 'I plate piece in one operation; that is', no press with a large enough bed to hold-the necessary dies to=blank= out the whole piece of metal by one action of the press. Instead, there may be several large'presses with one die in one press, another die in another press, and the third die in a third press. A side plate could then be produced by run ning the sheet of metal first throughthe first press where one-third is blanked out, then on to the next press where thenext third, or center, is blanked out,'and then on to the last press where the remaining end third is blanked out. This operation would blank the sheet of metal into the form shown in FIGURE 6, after which the side rails could then be formed into the-completed side rails. The hanger side platescould then be blankedoutby presses and formed so that they fit and are welded into place on the respective side rails. Bracing and the cross'members could then be welded into place to provide one suspension assembly. I Y

Accordingly, the description of the proceduresof -th invention herein should be interpreted in an illustrative rather than a limiting sense, and the scope of the invention should not be limited, except as defined in the appended claims. 3

What is claimed is:

1. A'process for producing a suspension component which comprises the steps of providing a single sheet of substantially flat metal plate, blanking a tandem side rail from said plate, said side rail comprising a substantially fiat plane of substantially rectangular shape, said side rail including a plurality of hanger sections depending therefrom with a'hanger section substantially disposed at each end thereof, each hanger section having a shape that decreases in cross section from top to bottom, ending in a rounded bottom edge, simultaneously forming an integral lining flange on each'of said hanger sections by turning the bottom and side edges such that in cross section the lining flange comprises a curve that sweeps from the plane of the hanger section and terminates in a straight line that is oriented at an angle approaching 90 with respect to the plane of the hanger section; and then forming upper and lower rigidifying channels on the Side rail by braking the upper edge of the side rail, and by braking the lower edge of the side rail in areas other than said hangersections, said rigidifying channels being disposed in a direction that is opposite to the direction of said lining flange.

2. The process of claim 1 including the step of integrally joining a hanger side plate to said side rail parallel to each hanger section, each hanger side plate being substantially similar in shape to the corresponding hanger section;- I I i a 3(The process of claim -1 including the step of integrally joining at least one reinforcing flange to the inside of said side rail between said upperand lower rigidifying channels.

4. Theprocess of claim l including the step ofintegrally joining said side rail to'anidentically formed side rail in parallel alignment therewith, by integrally joining suitable cross members therebetween. H

5. The process of claim 4 including the step of integrally joining a reinforcing flange'to each end of each'cross member to reinforce the connection between the cross member and eachside rail: 1 f t 6; A process for producing a suspension-component which comprises the steps of providing a singlesheet of substantially flat metal plate, blanking a'tandem side rail from said plate, said side=rail comprising a substantially flat planeof substantially rectangularshape,'said side'rail including a plurality of hanger sections depending therefrom with a hanger section substantially disposed at each end thereof, each hanger sectionhaving a-shapethat de creases in -cross section-from top to bottom, ending ,in'a rounded bottom edge; simultaneously forming an integral lining flange on each of said hanger sections by turning the bottom and side edges suchthat in cross section the lining flange comprises a curve that sweeps from the plane 13 of the hanger section and terminates in a straight line that is oriented at an angle approaching 90 with respect to the plane of the hanger section; and then forming upper and lower rigidifying channels on the side rail by braking the upper edge of the side rail, and by braking the lower edge of the side rail in areas other than said hanger sections, said rigidifying channels being disposed in a direction that is opposite to the direction of said lining flange; thereafter integrally positioning said side rail parallel to an identically formed side rail, positioning suitable cross rnernbers therebetween, and integrally joining the side rails and cross members to one another.

7. The process of claim 6 including the step of integrally joining a plurality of hanger side plates to said side rails adjacent each of said hanger sections,

8. The process of claim 6 including the step of integrally joining a plurality of reinforcing flanges to the inside of each side rail between the upper and lower rigidifying channels.

9. The process of claim 6 including the step of reinforcing the connection between each side rail and the cross member end integrally joined thereto, by integrally joining a reinforcing flange to said connection.

10. The process of claim 7 wherein each cross member is integrally joined at each end to a hanger side plate.

References Cited UNITED STATES PATENTS 2,204,087 6/ 1940 Konetsky.

2,244,847 6/1941 Oeckl et a1 29155 2,907,579 10/1959 Masser 280-104.5 X 3,004,324 10/1961 Macomber 29-155 3,022,087 2/ 1962 Black.

3,074,738 1/1963 Ward.

3,137,922 6/1964 Schumacher 29--155 FOREIGN PATENTS 435,058 5/1948 Italy.

THOMAS H. EAGER, Primary Examiner. 

1. A PROCESS FOR PRODUCING A SUSPENSION COMPONENT WHICH COMPRISES THE STEPS OF PROVIDING A SINGLE SHEET OF SUBSTANTIALLY FLAT METAL PLATE, BLANKING A TENDEM SIDE RAIL FROM SAID PLATE, SAID SIDE RAIL COMPRISING A SUBSTANTIALLY FLAT PLANE OF SUBSTANTIALLY RECTANGULAR SHAPE, SAID SIDE RAIL INCLUDING A PLURALITY OF HANGER SECTIONS DEPENDING THEREFROM WITH A HANGER SECTION SUBSTANTIALLY DISPOSED AT EACH END THEREOF, EACH HANGER SECTION HAVING A SHAPE THAT DECREASES IN CROSS SECTION FROM TOP TO BOTTOM, ENDING IN A ROUNDED BOTTOM EDGE; SIMULTANEOUSLY FORMING AN INTEGRAL LINING FLANGE COMPRISES A CURVE THAT SWEEPS FROM THE PLANE THE BOTTOM AND SIDE EDGES SUCH THAT IN CROSS SECTION THE LINING FLANGE COMPRISES A CURVE THAT SWEEPS FROM THE PLANE OF THE HANGER SECTION AND TERMINATES IN A STRAIGHT LINE THAT IS ORINETED AT AN ANGLE APPROACHING 90* WITH RESPECT TO THE PLANE OF THE HANGER SECTION; AND THEN FORMING UPPER AND LOWER RIGIDIFYING CHANNELS IN THE SIDE RAIL BY BRAKING THE UPPER EDGE OF THE SIDE RAIL, AND BY BRAKING THE LOWER EDGE OF THE SIDE RAIL IN AREAS OTHER THAN SAID HANGER SECTIONS, SAID REGIDIFYING CHANNELS BEING DISPOSED IN A DIRECTION THAT IS OPPOSITE TO THE DIRECTION OF SAID LINING FLANGE. 